Abstract 16738: Correlation Between Appropriate Use of Coronary CT Angiography and Downstream Resource Utilization

Abstract

Introduction: Limited data exist regarding the correlation between the appropriateness of use of coronary CT angiography (CTA) and downstream resource utilization (RU). Methods: Data from the Advanced Cardiovascular Imaging Consortium, a statewide CTA registry were linked to Blue Cross Blue Shield of Michigan claims data. Based on the 2010 appropriate use criteria, the group was divided into: appropriate (A), inappropriate (I), uncertain (U) and unclassifiable (UC). CTA findings and RU (hospitalizations, invasive angiography, revascularizations, stress testing) at 1 year were compared. Results: The study group consisted of 2307 patients (A =1582, I = 276, U = 195 and UC = 254). The most common indication among the I group was use of coronary CTA for CAD screening (32%). Compared to the A group, patients in the I group were older and more often male, and had higher prevalence both nonobstructive (<50% stenosis, 69.2% vs. 54.1%, p<0.0001) and obstructive (≥50% stenosis, 27.8% vs. 19.3%, p<0.0001) CAD. No significant difference was noted between the A and I groups with respect to overall downstream resource utilization (46.9% vs. 44.6%, p = 0.47), invasive procedures (15% vs. 15.2%, p = 0.94) or noninvasive testing (43.1% vs. 40.6%, p = 0.44). On multivariate analysis among all patients, the finding of obstructive CAD was the strongest predictor of overall resource utilization (OR 5.33 [95% CI 3.51-8.10]) followed by acute presentation (OR 2.1 [95% CI 1.48-2.98]) ; inappropriate use was not a significant predictor (OR 0.78 [95% CI 0.51-1.19]). Conclusions: In this population-based cohort, 68.5% of patients were appropriately referred for CTA. Appropriate use did not correlate with downstream resource utilization events, which were driven strongly by CTA findings. Additionally, patients deemed inappropriate for CTA had higher burden of CAD, with implications for early detection and prognosis in these patients. Further studies are needed to adjudicate appropriateness of use of coronary CTA.